This invention relates to a wire press-clamping method for press-clamping a conductor of a wire to a press-clamping terminal.
There is known one related wire press-clamping method for press-clamping a conductor of a wire to a press-clamping terminal, in which an electrically-conductive member is provided (see, for example, Patent Literature 1).
As shown in FIG. 10, the press-clamping terminal 70, disclosed in Patent Literature 1, includes an electrical contact portion 71, and a wire press-clamping portion 72. The wire press-clamping portion 72 includes a conductor press-clamping portion 75 for press-clamping the conductor 74 of the wire 73, and a sheath press-clamping portion 77 for press-clamping a sheath 76 of the wire 73. The narrow electrically-conductive member 78 is provided at the conductor press-clamping portion 75, and extends over an entire width thereof. The electrically-conductive member 78 fills in a gap, formed between the conductor press-clamping portion 75 and the conductor 74 during the press-clamping operation, in a gastight manner.
There is known another related wire press-clamping method for press-clamping a conductor of a wire to a press-clamping terminal, in which serrations are formed at a wire barrel portion (see, for example, Patent Literature 2).
As shown in FIG. 11, the press-clamping terminal 80, disclosed in Patent Literature 2, includes the wire barrel portion 82 and an insulation barrel portion 84 which are formed integrally with each other, and are juxtaposed in a direction of a length of a terminal body 81. The conductor 86 and a sheath end portion 87 of the wire 85 are press-clamped respectively to the two barrel portions 82 and 84, and therefore are connected thereto. The plurality of parallel serrations 88 are formed at the wire barrel portion 82, and extend in one direction. The serrations 88 prevent the conductor 86 of the wire 85 and the wire barrel portion from being displaced relative to each other at areas of contact between the inner periphery of the wire barrel portion 82 and the conductor 86 during the time when the conductor 86 of the wire 85 is connected to the wire barrel portion 82 by press-clamping.    Patent Literature 1: JP-A-2000-251961 (Pages 2 to 3, FIG. 1)    Patent Literature 2: JP-A-11-003733 (Pages 2 to 3, FIG. 1)
When a conductor of a wire is electrically connected to a press-clamping terminal by press-fastening (press-clamping), a mechanical strength of the press-fastened conductor usually decreases to a level lower than a breaking strength of the conductor. Here, whether the conductor is made of copper or aluminum, the degree of decrease of the mechanical strength thereof is generally the same. However, the aluminum conductor is lower in breaking strength than the copper conductor, and therefore there is a fear that the aluminum conductor cannot withstand an applied force when a wire harness is assembled. Namely, there is a fear that the aluminum conductor is cut during the press-fastening (press-clamping) operation since the aluminum conductor is relatively low in strength, and therefore it is desired that the aluminum conductor will not be squeezed during the press-fastening operation. However, unless the aluminum conductor is adequately squeezed, there arises a problem that the area of contact of the conductor decreases, so that the electrical resistance increases.
Therefore, when the conductors 74 and 86 in the above Patent Literatures 1 and 2 are made of aluminum, there is countered a problem that the area of contact of the conductor decreases, so that the electrical resistance increases, which makes it difficult to flow an electric current of a predetermined value through the wire.